Self locking strap buckle



FIG. 1 is a top perspective view of a self locking strap buckle, showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a side elevational view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a rear elevational view thereof. 

The ornamental design for self locking strap buckle, as shown and described. 